Churcher C. Beginning SQL Queries: From Novice to Professional

Apress, 2008. — 240 p. — ISBN-13 (pbk): 978-1-59059-943-3, ISBN-10 (pbk): 1-59059-943-8.Relational Database Overview.
Simple Queries on One Table.
A First Look at Joins.
Nested Queries.
Self Joins.
More Than One Relationship Between Tables.
Set Operations.
Aggregate Operations.
Efficiency Considerations.
How to Approach a Query.
Common Problems.
Sample Database.